The present invention relates to chalk line dispensers, and more particularly, to the housings of chalk line dispensers.
Chalk line dispensers are widely employed to mark straight lines along a work piece or work place. Generally, the chalk line dispenser housing or casing is comprised of a pair of mating elements which interfit and define a chamber for storing chalk and the line about a spool. Lap joints are commonly employed along the interfitting surfaces of the mating elements to prevent chalk leakage from the chalk chamber. Exemplary of such devices are those illustrated in Kahmann U.S. Pat. No. 4,765,557, Hwu U.S. Pat. No. 4,926,562, and Lane et al U.S. Pat. No. 4,197,656. It is difficult, however, to produce a tight fit for a half lap joint in normal manufacturing processes using standard tolerances and materials. As a result, the seal in conventional casings is often loose enough to permit some leakage of chalk powder from the chalk storage chamber, particularly when there are impacts upon the casing.
Accordingly, it is an object of the present invention to provide a novel casing for a chalk line dispenser which ensures a tight fit between its sections to prevent leakage of chalk powder from the chalk storage chamber.
It is also an object to provide such a casing which employs a seal which does not require relatively close tolerances to be effective.
Another object is to provide such a seal which enables simple and rapid assembly of the casing sections.
Still another object is to provide such a casing which may be readily fabricated from economically produced component parts to produce a long lasting rugged assembly.